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2022-09-24 03:23:45 By : Ms. Diamond Shi

This article was published more than 3 years ago

One of the reasons the lawn remains the ubiquitous feature of our landscapes, even in small urban gardens, is that humans are wired for tribalism, says biologist Doug Tallamy. Conformity is a sign of belonging, and who wants to be the first person on the block to shrink, if not ditch, that immutable, non-threatening, neighborly lawn? Well, Tallamy does, for one.

Tallamy became the darling of the native plant community with his 2007 book, “Bringing Nature Home,” which provided a scientific basis for replacing the exotic ornamentals that dominate our gardens with home-grown perennials, ground covers, shrubs and trees. Indigenous flora, Tallamy says, supports far more of the insects, birds and other creatures that co-evolved with them than a ginkgo from China, say, or an azalea from Japan.

In his latest book, “Nature’s Best Hope,” he presents a full-blown manifesto that calls for the radical rethinking of the American residential landscape, starting with the lawn.

Welcome bugs into your yard. You might just save the world.

Tallamy, an entomology professor at the University of Delaware, makes a compelling case that the loss of forests, meadows, wetlands and the rest to development over the past 200 years has left wildlife clinging to ever-shrinking, fragmented habitats.

But if the calamity is staring us in the face, so, too, is the solution. There are almost 130 million parcels of residential land in the United States that together can restore lost biomes. If everyone started to reduce that biological wasteland known as the lawn in favor of native plants, including trees, Tallamy says we could create one big connected habitat for species we are driving to the brink.

The idea of planting gardens for wildlife and shrinking the lawn isn’t new, but Tallamy wants to enlist every home garden in the battle to address the loss of biodiversity. The need has never been more urgent, he says. For example, bird populations have declined by almost a third in the past half-century, according to a 2019 study.

Tallamy wants us to rethink our relationship to plants and animals, particularly the idea that “nature” is something set aside in preserves and parks, something separate from our daily lives and something we go to visit. He calls this idea of separation one of the big mistakes of our approach to conservation. Another is that we are content to let the professional ecologists deal with it. “We can no longer leave conservation to the conservationists,” he says. Another mistake has been in focusing on saving endangered species rather than endangered ecologies.

So, what does he suggest?

Envision your property, he writes, “as one small piece of a giant puzzle, which, when assembled, has the potential to form a beautiful ecological picture.” He calls it the Homegrown National Park.

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Tallamy and his wife, Cindy, live on a ­10-acre lot in southeast Pennsylvania, just north of the Mason-Dixon Line and close to the university campus in Newark, Del. The parcel incorporates a stream valley and was once open hayfields as part of a larger farm.

Twenty years after they moved there (and built a house), the predominant plants are trees — oaks, sycamores, butternuts, maples, pawpaws and more — that have been planted by Tallamy or by themselves, as self-sown volunteers.

He has removed the invasive thugs, such as autumn olive and oriental bittersweet, and has done some editing of the trees, but much of the property is not so much a designed landscape as sloping fields reverting to forest. A sentinel tree in front of the house represents this woody regeneration — a handsome white oak, now 30 feet tall, that grew from an acorn Tallamy planted.

Not all native trees support wildlife, but the oak is one of Tallamy’s keystone plants. Where he lives, he says, 511 species of caterpillar use oaks. The caterpillars, in turn, are essential food for nestling songbirds and reflect a thriving food web that is the hallmark of a healthy ecology.

“Insects are the oxygen that drives ecosystems,” he says. As we walk the property on a cold winter’s afternoon, we see a tiny chickadee-like bird flitting through the canopy of a spindly self-sown tree. The tree is a black cherry, and the bird, Tallamy tells me, is a golden-crowned kinglet. It is feeding off little caterpillars perched in the upper branches, even in frigid January.

Since he returned native trees and other plants to the property, he has identified 905 species of moths and 55 different birds. Such biodiversity “certainly wasn’t happening when this was mowed for hay,” he says.

Turning Tallamy’s manifesto into reality faces some obvious obstacles, not least the prevailing cultural norms of what constitutes an acceptable residential landscape, with the lawn at its core.

He says you don’t have to remove all of your lawn — in fact you shouldn’t, so that you can telegraph to the world that you’re still caring for the landscape. But he points out that turfgrass covers more than 40 million acres in the United States, an area the size of New England, and we are adding 500 square miles of it each year.

The movement away from the lawn is already evident. He notes that in Southern California, water companies give rebates to homeowners who rip out irrigated lawns in favor of drought-tolerant plants. Some sort of reward could be extended to everyone who converts turf to planted yards that support biodiversity.

He advocates people lobby or join homeowner association committees to effect change, saying that resistance can be overcome “by designing artful landscapes” with native plants. In his imagined Homegrown National Park, pesticides are banned, and night and security lights should be motion-activated only, so as not to disrupt nocturnal creatures.

Looser plantings should be confined to the backyard, he says, and the more public front yard should be managed to look neat. “This is where the knowledge comes in,” he says.

“Nature’s Best Hope” is not a practical how-to planting or design manual, which may frustrate some readers. A 2014 book Tallamy wrote with author and photographer Rick Darke, “The Living Landscape,” explores designed plant communities in more detail.

My take? In recent years, gardening has moved away from its traditional realm of pure aesthetics toward something more ecologically driven. Gardening for pollinators and other desired wildlife is in vogue. The trophy lawn is still cherished across the land, but people, I sense, are more relaxed about weeds in their grass, use fewer pesticides and want to plant for beneficial insects. No informed gardeners would continue to use plants that are known to be invasive in their area.

This is all to the good, but a garden is not a nature preserve; it’s a designed space created to give us pleasure, emotional sanctuary and an appreciation for nature. For me and many others, a large part of that joy aligns with Tallamy’s goal — in welcoming and harboring animal life, especially birds, amphibians, reptiles and invertebrates.

I love native plants and their cultivated varieties, but I couldn’t limit myself to them.

Tallamy says you can still have 30 percent of nonnative varieties and accrue the ecological benefits of a native plant landscape, at least in a study of Carolina chickadee breeding conducted by one of his students, Desirée Narango.

Assuming you can have the best of both worlds, a garden for people and for wildlife, what is needed now is the practical guidance and the model gardens that will light the way, says Claudia West, a landscape architect whose firm, Phyto Studio, specializes in ecologically functioning design.

West worries that those who want to live in a Homegrown National Park will think that a naturally inspired landscape means one that will look after itself. She is the co-author with her colleague Thomas Rainer of “Planting in a Post-Wild World,” which argues that ecologically driven landscapes require more, not less, proficiency than traditional landscapes.

“I’m a huge fan of Doug Tallamy, and what he’s doing is exactly what we need, a big cultural change,” West says, “but what we need now are the models to bring this down to the reality of the culture, people who don’t garden, for example.”

One place where that is being done is the former Dupont estate near Wilmington, Del., named Mt. Cuba Center. The public garden includes a meadow, woodland and aquatic gardens, and, in the formal area close to the house, a traditional herbaceous border, but one planted in native plants.

Tallamy says residents can plant pocket meadows just a few feet square. Planting and maintaining a meadow of lawn size or greater, far from being easy, is one of the most demanding forms of gardening because you have to establish desired grasses and wildflowers under immense weed pressure. Keeping them weed-free requires knowledge, vigilance and work.

Meadow installations “I have seen that have been successful beyond the first five years, I can probably count them on one hand,” West says.

George Coombs, Mt. Cuba’s director of horticulture, says native trees — various oaks, maples, tulip trees, dogwoods, redbuds, for example — have always been incorporated into home gardens. Using native perennials, however, “requires a bit of a willingness to go against the grain.” The same might be said for native shrubs as alternatives to such popular fare as azaleas, lilacs, most hydrangeas and roses, for example.

Another consideration is that many homeowners leave the planting and maintenance of their properties to landscape contractors whose plant palette and care routines are not geared to this brave new world.

Tallamy says the shift he’s proposing opens up new business opportunities for them across the vast domestic landscape.

West says there is a cadre of progressive landscapers who “absolutely get it. They’ve read the books, they have the skills and the tools.” But they don’t have the clients, or enough of them. “It’s a chicken-and-egg thing.”

H. Keith Wagner, a landscape architect in Burlington, Vt., says the ecological gardening movement cannot reject the importance of beauty in designing a garden. When he built his home, he placed a six-acre grassy meadow in front of it, which he mows once a year after bird-nesting season. “But I’m in a rural situation. It’s going to be a slow change until cities and suburbs see the positive outcome it can provide.”

“You can start by adding a few native plants to your existing landscape and loosen the reins a little,” Coombs says. “You don’t have to go from zero to 100 right away.”

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